In order to allow users with capability 'moodle/course:managefiles' to select, for instance, pictures already uploaded to the server in the frame of the definition of the content of some item I added the class surveypro_file_info and I called it form the function surveypro_get_file_info of lib.php
In order to allow users with capability 'moodle/course:managefiles' to select, for instance, pictures already uploaded to the server in the frame of the definition of the content of some item I added the class surveypro_file_info and I called it form the function surveypro_get_file_info of lib.php
I am finally satisfied of the code.